The present invention relates to an ultrasonic diagnostic apparatus of the reflection type, and a method of diagnosis using the apparatus. In particular, the invention relates to a method and apparatus for determining acoustical homogeneity of an object.
The present inventors have developed a method of measuring the speed of sound in an object by utilizing an ultrasonic diagnostic apparatus of the reflection type. A conventional method of measuring the speed of sound by reflection has been disclosed, for example, in D. E. Robinson, et al., "Measurement of Velocity of Propagation from Ultrasonic Pulse-Echo Data", Ultrasound in Med. and Biol., Vol. 8, No. 4, pp. 413-420, 1982. According to this method, ultrasonic wave beams are transmitted from two directions to a reflector in the object as a common target, the time until the waves reflected by the target are received is measured, and a degree of refraction at the interface between the object and an acoustic coupling liquid is estimated from the data thus obtained, thereby to find the speed of sound in the object. This method makes it possible to find the average speed of sound in the object, but is not capable of obtaining data that represent acoustical homogeneity of the object.